De novo colorectal cancer after kidney transplantation: a systematic review and meta-analysis

BackgroundKidney transplant (KT) patients have higher risks of developing de novo colorectal cancer (CRC) compared to the general population. However, there is still a knowledge gap in their clinical characteristics, as most single- or multi-center efforts are underpowered and lack generalizability. MethodsPubMed, Web of Science, Cochrane CENTRAL, and Scopus databases were queried for studies published until July 22nd, 2024. Studies reporting the clinicopathologic characteristics and outcomes of de novo CRC among KT recipients were included. ResultsThere were 49 articles included involving 1855 KT patients who developed CRC. The mean time from transplantation to CRC diagnosis was 8<middle dot>7 years (95%CI 7<middle dot>2, 10<middle dot>3 years; I2 = 98<middle dot>3%). De novo CRC was most commonly located in the ascending colon (43<middle dot>6%; 95%CI 29<middle dot>5%, 58<middle dot>9%; I2 = 55<middle dot>3%), and 37<middle dot>1% had advanced CRC at diagnosis (95%CI 22<middle dot>3%, 54<middle dot>8%; I2 = 64<middle dot>1%). Although 68<middle dot>8% underwent curative intent treatment (95%CI 45<middle dot>4%, 85<middle dot>4%; I2 = 65<middle dot>4%), pooled 5-year survival rate was 31<middle dot>8% (95%CI 10<middle dot>5%, 65<middle dot>1%; I2 = 82<middle dot>5%). ConclusionsDe novo CRC was diagnosed in under 10 years after KT, and nearly 40% of patients already have advanced stage disease at diagnosis. The pooled rate of 5-year survival was 31.8%. However, there was wide heterogeneity between studies and further research is required. PROSPERO Registration: CRD42023415767.